I'm 50, I've known my in-laws for nearly 30 years and they are as cold and polite as the day I first met them.
I could be DH's brand new girlfriend for the warmth they show to me.
We probably all know each other too well and yet not at all. Thirty years ago MIL certainly knew more about gardening, today I'm not so sure.
They always ask DH's opinion about stuff even if I'm the person most likely to have dealt with that aspect of our lives.
DH is no help when I want to let off steam about this. I need a post visit vent!